DE3225091C2 - Smoke filter element - Google Patents

Description

The present invention relates to a smoke filter element according to the preamble of claim 1. In particular The invention relates to a tobacco smoke filter.

Various forms of cigarettes are in the prior art filter known, where the sucked smoke on ver is diluted in various ways by supply air. So describes DE-OS 30 11 959, for example, a cigarette filter which is a rod-shaped filter element with an air-permeable Cover sheet is surrounded, the cover sheet and the rod-shaped Filter element several extending in the longitudinal direction Has grooves and is surrounded by a mouthpiece material, which is provided with flow openings. In U.S. Patent 1,718,122 describes a filter element that has a filter core and a smoke-tight envelope surrounding the filter core has, wherein the envelope is corrugated in the longitudinal direction and thus has channels for drawing in ambient air. Close Lich discloses the AU-PS 240 650 a filter element that likewise with a sheathing corrugated in the longitudinal direction Formation of intake channels is surrounded. This in the state of the Filter elements known in the art all have the disadvantage on that they are relatively inflexible because of the air supply only to a specific one, due to the filter construction fixed way.

The present invention is therefore based on the object specify a filter element with air dilution, which much can be used on both sides and flexibly.

This task is characterized by the characteristics of the Claim 1 solved. Advantageous configurations are in the Subclaims specified.

The invention filters and filter elements created, which are suitable for smoke and other filtering uses, but below only explained using the example of cigarette filters and be represented as this is the currently commercial most interesting application is.

The invention provides, among other things, a smoke filter element with a filter core, a smoke-tight one  Envelope that surrounds the core, at least an (inner) passage or channel that lies between the impervious envelope and the core formed as well is open at one end of the element, and at least another (outer) passage or channel leading through the outer surface of the impermeable casing is bordered and extends to one end of the element. The impermeable covering is advantageously so profiled to form the inner and outer channels, d. H. it can be longitudinally grooved or corrugated to to form the channels; through the invention a smoke filter element with a filter core and one corrugated smoke-proof enclosure created, which latter first (inner) channels between the um shell and the core, which extends in the longitudinal direction of the Extend smoke filter element to one end thereof, and further (outer) channels outside the envelope, which are in the longitudinal direction of the element to one end of this ele extend, forms.

The filter elements according to the invention are first Line for use as a filter with a cover sheet or lace material which determines the passage permitted from outside air into the other (outer) channels, if the filter is pulled during use. A sol This ventilating tip material can be used in the manufacture the filter around the impermeable casing or it can be the tip wrapper that the Filter element in the manufacture of a filter cigarette is connected to a tobacco rod. By the present Accordingly, the invention also becomes a cigarette filter created, with a filter core, one the core comprehensive smoke-tight envelope, a die impermeable covering surrounding lace material, with at least one (inner) channel between the  impervious envelope and the core formed and as well is open at one end of the filter, and at least one another (outer) channel that is between the impermeable gene wrapping and the lace material formed as well one end of the filter is open; the lace material he leaves when using the filter on this the outside air is drawn in laterally the lace material in the further (outer) channel or, the other (outer) channels.

The channels can only extend over part of the length of the Elements or filters, but it can also one, several or all of one end of the element or Filters reach to the other end; any channel can be essentially constant over its length Cross section or (especially if it is different from extends to the other end of the filter or element) be narrowed in an end region and / or intermediate region. The channels can be in the axial direction of the element or Filters or run along a curved path.

If the impermeable covering with longitudinal Grooves or corrugations are provided to the mentioned Channels can form the grooves or curls thus extend over the full length of the casing (also if the grooves or corrugations at one end or intermediate area may be smaller) or they can end at an end or intermediate part of the envelope (e.g. on an undulating or circumferential direction corrugated or corrugated area) so that (at least in the finished filter) one or more channels there are closed. The impermeable covering can also have other profiled configurations to the Form passages or channels, e.g. B. in the form of (e.g. round) balls or wart-shaped embossing.  

In particularly preferred embodiments of the invention the impervious envelope has a circumferential groove into which at least one of the outer channels opens, this groove ver usually closes the inner channel or the inner channels. For filter cigarettes according to the Er invention, which contain such elements, a Venti lation through the tip material directly into the circumferential groove and thus in the communicating outer channel or the communicating outer channels may be provided; e.g. B. can have ventilation perforations in the lace material be seen in a circumferential direction Ring are aligned with the circumferential groove. It Various configurations are possible: e.g. can the circumferential groove in the middle along the envelope be seen, with its inner and outer channels in opposite directions to both ends of the Ele extend; or the peripheral groove can be at one end of the element where the impermeable order envelope corrugated in the circumferential direction or otherwise is shaped that the inner and outer channels that are extend from the circumferential groove to the other end of the element, be closed at the relevant end; at a Another variant is the circumferential groove on one End of the wrapping and is open towards that end, being the inner and outer channels differ from one another Extend end; other embodiments include more re circumferential grooves that are spaced along the envelope and z. B. at opposite ends of the envelope are located. The for the production of a fiction elements of this type certain impermeable order cover can simply be preformed in the normal way, to form the desired channels, each area which is to form a circumferential groove, smooth and unprofiled is left; it has been shown that the smooth, unprofiled areas by themselves the shape of scope  accept grooves if such a profiled casing around the core. This is particularly effective if the corrugations are to form the channels.

If the channels are embossed or otherwise ge molded impermeable envelope are to be formed, the core expediently has a substantially con constant circular cross-section and the tip material in a corresponding manner essentially has the form of a straight circular cylinder.

If the inner and outer channels do not cross the stretch the full length of the wrapper, they become habitual Lich open at the same end of the element or filter and usually in the same place along the filter, e.g. B. at the other end of the filter, be closed; none however, these characteristics are essential. The first mentioned and the latter channels can be in different places be closed along the filter, each of which one end of the element or filter or between its Ends.

The filter core of the element or filter according to the inven dung can be made from a wide variety of cigarette filter mats rials exist, e.g. B. from connected or unconnected Staple fibers or fiber cables (made of cellulose acetate or Polyolefin, etc.), crepe paper or an air permeable Foam. The core can be the same over its length shaped or non-uniform structure and composition to have; it can be in one piece or assembled, e.g. B. an envelope and / or separate plugs with the same or different properties (e.g. pressure drop or Flow resistance) and / or composition; the nucleus can cover all or part of it extend the length of the element or filter and if  the core is composed of two or more plugs, can adjoin or spaced adjacent plugs stands up. The core can be uncovered or one Plug casing made of a perforated and / or natural made of smoke permeable material; the core can instead, an impermeable plug casing or integral (e.g. melted by heat or solvent) Have skin. The core can ent particulate additives keep that evenly distributed in it or in at least an area or space between two stops fen can be localized; the core can be profiled th (e.g. longitudinally grooved) circumference and it can have one or more internal channels or cavities have filled or empty. The core may contain one or more components that do not Filter effect only to increase the Pressure drop or flow resistance serve, and as Element filter core and filter according to the invention or in this can be a plug of high pressure drop and low reluctance or filtering out together coarse fibers or combined embossed Plastic, metal (e.g. aluminum) or other foil be used. In some embodiments gives the impermeable covering a cavity or a recess at one end of the filter element or filter is open and can be used when in use Take or this cavity in the wrapped tobacco rod the filter cigarette in question may be arranged or on the mouth ends of which are open.

During the filter core of the elements according to the invention be a composite structure of the type mentioned above, e.g. B. from adjacent or in the longitudinal direction spaced plugs can make the profiled impermeable wrapping that extends the full length  of the element extends, the element to a total coherent, uniform structure.

The impermeable covering is advantageously a Laminate of paper and a thermoplastic polymer, e.g. B. a paper / thermoplastic / paper laminate, the Plastic layer preferably made of a polyolefin, e.g. B. Polyethylene. Such a laminate has good Embossing properties and maintains its impermeability and embossed configuration well. The impermeable order is wrapped around the core preferably by an over lobed and glued hem attached; instead can but also at the core through one or more longitudinal nale adhesive strips are attached.

The lace material can be breathable if it is however, the lace cover sheet or lace wrapper forms that connects the element with a tobacco column, it more often consists of an essentially impermeable casual material that has perforations in open connection with the other or outer channels stand. The element can be wrapped in air have permeable material, which the filter gives smooth outside and around the filter cigarette making the top cover page or the Lace wrapping (or a lace or connecting ring) is generally not required such.

When used as part of a filter cigarette, this can Filters according to the invention (via the inner channel or the inner channels between the impermeable covering and the core) a detour for the smoke around part of the Form length of core and you can do it depending different from the filter structure used  achieve controlled effects, such as using special Embodiments to be explained below becomes. In these cases, however, the core shows no smoke impermeable layer between itself and the impermeable wrap. The outer channel or the outer Ka channels between the impermeable casing and the spit Zen material can be open at the mouth end, so that Venti air is sucked into it and directly into the mouth of the smoker, whereby they have only little or doesn't mix with smoke at all. An outer channel can instead also be open towards the end of tobacco, so that the in ventilation air sucked in upstream to tobacco rod flows and then downstream through the filter core. A narrowing of a channel can change the degree and direction the flow in the non-restricted part or not influence or determine restricted parts. A filter According to the invention, at least one outer channel have, which is only open at the mouth end, and at least another such channel that is only on the other end is open; in a corresponding manner, at least one inner channel only at the end of the mouth and at least one other only be open at the other end.

The elements according to the invention can be used in purpose moderate by first making the Core (as endless or discrete, finite Rod), the impermeable covering brings material into the desired shape (e.g. by waves), and the molded or profiled impermeable envelope winding around the core and attached to it; then a lace material around the impermeable um be wrapped; this lace material can do that Top cover sheet or top serving that in the production of a filter cigarette in conventional way to connect the element to a tobacco rod serves.  

The core is usually considered to be endless, continuous Rod are formed, which then continues with the previous one profiled impermeable wrapping is wrapped; the resulting endless or continuous composite The structure can then be cut into pieces of a certain length be cut. If desired, a wrapping made of an air-permeable material the composite structure of the core and the pro filleted wrapping to be placed before the rod in the Pieces are cut. For the production of filters cigarettes will be a wrapped tobacco stick at each end a piece of double length of this product, then a ventilation tip wrap is applied around the tobacco sticks with the arranged between them Connect element or filter and the resulting one The combination is finally cut in half to make two filter cigarettes. That was initially continuous filter or element is made for the delivery to the filter cigarette manufacturer more normal in pieces with an even number (e.g. six) cut up from units and the filter cigarette Steller then cuts these pieces into pieces twice Element length with which the filter cigarette in the be produced in the manner described above. It should understand that the filter manufacturer originally supplied rods that are an even number of individual filter elements have a corresponding length and from which finally pieces with simple filters element length are formed in the event that filters or elements of simple length according to the invention the inner and outer channels open at only one end and end just before the other so that the two ends of the filter or element are different, similar Can have ends, d. H. that the channels at a rod with a length that is an even number of individual  Corresponds to filter elements, open at both ends or can be closed at both ends, depending on whether the channels in the final filter cigarette to tobacco should be open towards or at the end of the mouth. Such bars double and multiple filter element lengths also fall subject of the present invention.

The impermeable covering practically does not radial pressure on the core and expresses their profiling te configuration preferably not in the core surface on. The impermeable covering is preferably with longitudinal grooves, grooves or corrugations preformed; these can be discontinuous, whereby the longitudinally grooved or corrugated pieces of one other through parts (e.g. smooth or transversely corrugated or can be grooved) are separated in the finished filter close the longitudinal channels formed by the envelope. Instead of corrugations, the impermeable covering also be embossed with dimples or warts, so that the End product is a network of random or regular Canals, here too can be those with the dimples provided pieces of the wrapper, if desired Sections to be separated or broken that are smooth or are shaped so that they canals in the finished product to lock.

The following are non-limiting implementations games of the invention with reference to the schematic, not to scale drawings, in which Identical parts are identified with the same reference symbols.

Show it:

Fig. 1 is a longitudinal section in a plane II of Figure 3 of a filter and element according to an embodiment of the invention, which are incorporated in a filter cigarette according to one embodiment of the invention.

FIG. 2 is a partial sectional view of the element and filter according to FIG. 1 in a plane II-II of FIG. 1;

FIG. 3 is a sectional view of the filter and element according to FIG. 1 in a plane III-III of FIG. 1;

Fig. 4 to 8 are longitudinal sectional views, corresponding to the ge according to FIG 1, of five different embodiments of filters and elements according to the invention, which are inserted in ent speaking filter cigarettes according to the invention.

Fig. 9 is a corresponding longitudinal sectional view of a white direct embodiment of the filter and element according to the invention;

FIG. 10 is a more scaled end view of the element and filter according to FIG. 9;

Fig. 11 is a longitudinal sectional view of yet another embodiment of an element, filter and a filter cigarette according to the invention;

. 12 and 13 are cross-sectional views in planes XII-XII and XIII-XIII of Fig. 11;

FIG. 14 is a perspective view of the filter element according to the invention which is used in the filter according to FIG. 11;

. Fig. 15 is a view similar to Figure 11 from a different guide shape of an element and filter of a filter cigarette according to the invention;

FIG. 16 is a perspective view of the filter element according to the invention which is used in FIG. 15;

Fig. 17 is a Fig. 16 similar view of another embodiment of a filter element according to the invention and

Figs. 18 to 20 are schematic longitudinal sectional views of embodiments of multiple length elements according to the invention.

The filter element shown in Figs. 1 to 3 consists of a filter core made of a plug 2 made of filter material, which is encased in a smoke-permeable (naturally permeable and / or perforated by smoke) or a smoke-impermeable plug cover 4 , and a smoke-impermeable cover 6 that touches the core; the filter is completed by a cover sheet or tip material 8 which surrounds the impermeable covering 6 be touching. The impervious envelope 6 has longi tudinal corrugations 10 which are closed at one end 22 of the filter by circumferential corrugations 12 and channels 14 ( FIG. 3) between the core and the impervious envelope and channels 16 between the impervious envelope and form the top material; all of these channels are open at the end 18 of the filter. The tip material 8 consists of a smoke-impermeable material, but it has a circumferentially extending ring of perforations 20 through which the channels 16 are in communication with the ambient air.

The tip material 8 is a lace cover sheet or tip wrapper which extends beyond the core and the opaque wrapper 6 and connects the element to a wrapped tobacco column 23 at the end 22 ; instead, it could also connect the element at the opposite end 18 to such a wrapped tobacco rod.

The impermeable covering 6 is a paper / polyethylene / paper laminate, which is embossed with the illustrated longitudinal and transverse corrugations and is fixed around the core by a conventional overlapped and glued seam around the core; it can also be attached to the core along one or more longitudinal adhesive strips. The impermeable sheath 6 neither compresses the core nor presses its pattern into the surface of the core.

The plug 2 can be made of any conventional smoke filter material, e.g. B. connected or unverbun which fibers or a continuous fiber cable (z. B. from cellulose acetate, viscose, polyester or polyolefin), from crepe paper, plastic foam, etc. If the plug 2 itself is a dimensionally stable body (z. B. by hardening or Polymerization connected s continuous cellulose acetate fiber cable), and a smoke flow between the core and the channels 14 is permissible, the plug casing 4 can be omitted. If the core 2 is a composite structure, which contains two or more adjacent or longitudinally spaced elements, however, a plug casing 4 will preferably see.

It had already been mentioned above that the filter can be connected to either a tobacco rod at either end 18 or end 22 . In the former case, pulling on the mouth end 22 causes outside air to flow through the perforations 20 , along the channels 16 to the end 18 of the filter, and then through the body of the filter from the end 18 to the end 22 , diluting the smoke flowing through the filter . When the end 22 of the tobacco rod is adjacent, pulling on the mouth end 18 causes the outside air to flow through the perforations 20 and along the channels 16 to the mouth end 18 so that the ventilation air gets directly into the smoker's mouth before it mixes with the aspirated or inhaled smoke. If the stop fenumhüllung 4 is missing or perforated and / or inherently smoke-permeable, smoke will flow from the stopper 2 into the channels 14 and then directly into the mouth of the smoker when using the filter, if the end 22 is attached to the tobacco rod or, if the end 18 is connected to the tobacco rod, directly into the channels 14 and then into the smoker's mouth via the stopper 2 . If the plug casing 4 made of a permeable filter material, e.g. B. paper, it can improve the particle retention of the filter as a whole.

The filters and elements according to FIGS. 4 to 6 are similar in construction to those according to FIG. 1 and their appearance in cross section through the parts which are grooved or corrugated in the circumferential direction and in the longitudinal direction is similar to that in FIGS. 2 and 3.

In the embodiment of FIG. 4, the stopper 2 is provided with a porous stopper cover 4 , which initially generates a low pressure drop so that smoke can pass through, but parts of the tobacco smoke are easily blocked by the constituent parts; the filter is connected at the end 18 to a coated tobacco rod 23 . When the illustrated cigarette is smoked, a significant proportion of the smoke is directed past the filter through the channels 14 during the first puffs. The degree of bridging of the filter decreases, however, the more the cladding becomes blocked in the following strokes, so that an ever larger proportion of the smoke must then flow through the entire length of the filter plug 2 . This arrangement helps to even out the flavor release during cigarette smoking. The flavor release of a conventional ventilated filter cigarette increases during smoking from a low, often insufficient starting value to a high, often intolerable final value; for a given total output, however, the filter of the type shown in FIG. 4 shows, in comparison, the initial value increased and the final value decreased, so that the quality of the smoke is more uniform.

In the embodiment according to FIG. 5, the stopper 2 is a structure composed of two elements 24 and 26 of different filter properties. For example, element 24 can produce a high pressure drop (flow resistance) and element 26 can produce a low pressure drop; the stopper cover 4 in this case preferably consists of a naturally porous material and / or is provided with perforations at least in the part surrounding the element 26 with the low pressure drop, and the filter is provided at the end 18 with a covered tobacco rod 23 , so that the element 24 high pressure drop is on the tobacco side. At the start of smoking, the smoke is therefore caused to flow past the element 24 with a high pressure drop by entering the element 26 with a low pressure drop via the channels 14 . As in the previous embodiment, the stopper cover 4 can be easily blocked or plugged, so that the extent of the passage of smoke during the cigarette smoking changes. The individual sections can be different and be selected so that the required filter properties result overall.

In the embodiment according to FIG. 6, the filter is again attached to the tobacco rod with the end 18 , but the stopper casing 4 consists of an impermeable material which is provided with perforations 29 at the closed ends of the grooves or channels 14 . The stopper 2 can be in one piece or again a composite structure composed of an element of high pressure drop adjacent to the tobacco and an adjacent element of low pressure drop, which is given by the perforations 29 um. In the initial puffs, the smoke flows from the tobacco rod through the channels 14 and the perforations 29 into the stopper 2 ; the perforations 29 eventually clog up, forcing the smoke to flow through the entire length of the plug 2 .

In the filter shown in FIG. 7, the core consists of a plug 30 , which produces a relatively high pressure drop and is adjacent to a plug 32 , which generates a relatively low pressure drop; the plugs 30 and 32 are wrapped in a plug cover 4 made of a smoke-impermeable material and are thereby connected. The smoke-impermeable casing 6 in this case has circumferential corrugations 12 in a central region along its length, from which longitudinal corrugations 10 extend to the opposite ends 18 and 22 of the filter. The filter is connected at its end 18 to a wrapped tobacco rod 23 by a tip wrapper 8 ; the tip covering 8 has a ring of ventilation perforations 20 which communicate with the channels 16 between the impermeable covering 6 and the tip covering 8 at the mouth end 22 of the filter. At the other end of the filter, the channels 14 between the impermeable casing 6 and the core are open to the tobacco. These channels 14 extend beyond the high pressure drop plug 30 and where they end at the upstream end of the low pressure drop plug 32 , the plug wrap 4 is provided with fine perforations 29 which initially allow smoke from the channels 14 can easily pass through it, which, however, is blocked after a few moves, so that an increasing proportion of the smoke is forced to flow over the full length of the core through both the plug 30 and the plug 32 . This not only provides the effect obtained with the embodiment shown in FIGS. 4 to 6, but also the degree of air dilution, which gets through the perforations 20 and the channels 16 in the smoker's mouth, from a relatively low initial value ( if the perforations in the stopper envelope 4 are open, so that the flow resistance for the smoke is low) to a relatively high end value (if these perforations are blocked, so that the resistance for the smoke flow increases to a maximum), so what causes the taste of the smoke given off is more even from the first to the last puff.

The embodiment according to FIG. 8 contains a filter core consisting of a stopper 50 made of a connected cellulose acetate fiber cable and an adjacent stopper 52 made of crepe paper, which are held together by a smoke-impermeable stopper covering 4 . The smoke-permeable sheath has longitudinal corrugations 10 which extend the full length of the core, so that channels 14 and 16 are formed which are open at both ends of the filter. A tip cover sheet or a tip cover 8 made of smoke-impermeable material with a ring of perforations 20 which open into the channels 16 connects the filter to a covered tobacco column 23 and represents the tip material of the filter.

In the embodiments according to FIGS. 1 to 8, the tip material of the filter consisted of a tip covering or a lace cover sheet, which connects the element with a covered tobacco rod. However, the tip material of a filter according to the invention can also be a conventional, smooth, air-permeable plug casing, as shown in FIG. 9. In this embodiment, the core is an integral filter plug 2 with a smoke-permeable plug casing 4 ; the impervious envelope 6 has corrugations 12 and 10 in the middle in the circumferential direction and at the ends in the longitudinal direction, as in FIG. 7. Around the impervious envelope 6 is a smooth plug envelope 40 by means of a conventional overlapped and glued seam attached from air-permeable paper, which is applied in a production step in the manufacture of the filter in an endless, continuous rod, which is then cut transversely into the individual filter pieces shown. Instead, the plug casing 40 could also consist of an air-impermeable material which has perforations which open into the channels 16 . The filter can be connected at one end or the other to a wrapped tobacco rod by a tip ring or wrap which has ventilation perforations communicating with the channels 16 between the wrap 6 and the outer plug wrap 40 .

It should be noted that the drawings are not to scale for clarity of illustration; in general, the radial depth of the corrugations 10 is greatly exaggerated and their number and the core diameter are reduced accordingly. In practice, essentially the entire diameter (about 8 mm) of a filter according to the invention is taken up by the filter core and the corrugations 10 (and 12 ) have a radial depth of, for example, about 0.25 to 1 mm, in particular about 0.5 mm . Where only one perforation is shown per channel 16 , perforation holes which are closer together can be used in practice, in which case two or more then communicate with each channel 16 . In Fig. 10, an end 22 of an element and filter of the type shown in FIG. 9 is shown in a more scaled front view. The core plug 2 can in practice have a diameter of about 8 mm and the corrugations 10 of the casing 6 can form about twenty-two inner and twenty-two outer channels 14 and 16, each with a depth of about 0.5 mm. Similar dimensions apply in practice to the other embodiments, which are shown in FIGS. 1 to 9 and 11 to 20.

The above and below often refer to the use of a corrugated, impervious wrap referenced it however, other forms of profiled are opaque casual wrappings possible. For example, the impermeable wrapping made of heavy, strong paper (e.g. 100 g / m² or more), such as cartridge paper exist in which longitudinal grooves or grooves are preformed, expediently with the help of profiling embossing rolls; the surface of the paper can be smooth there be left where the formed by the wrapper Channels should end.

In the embodiments according to FIGS . 11 to 20, the filter element or the filter element rod each contain a filtering core (with a stopper 2 and a smooth, smoke-permeable or smoke-impermeable stopper cover 4 ), which in a smoke-impermeable envelope 6 with longitudinal corrugations 10 is wrapped, which forms longitudinal channels 14 between the casing and the core and outer longitudinal channels 16 channels. In the elements shown in FIGS. 11 to 17, the impermeable sheath also forms a circumferential groove 80 which communicates with the external grooves or channels 16, as shown, extending therefrom to one end of the filter. In use, the filter element is surrounded by a ventilating overwrap tip 8 and connected to a wrapped tobacco rod 23, the top casing 8 has a ring of ventilation perforations 20 which open into the circumferential groove 80th

In the embodiments according to FIGS. 11 to 14, inner and outer channels extend in the longitudinal direction from the circumferential groove to both ends of the filter rod. . In the leadership From form according to Figures 15 and 16, the impermeable sheath at the end adjacent the tobacco rod end of the filter in the circumferential direction extending corrugations 12 on completion of the circumferential groove and the outer channel toward the tobacco rod; the circumferential groove is located directly next to the corrugations running in the circumferential direction and the corrugations running in the longitudinal direction of the envelope, it extends from it to the mouth end of the filter. Which can be inserted in the same manner in a filter cigarette in the element according to FIG. 17, as FIGS. 11 and 15, the circumferential groove 80 at one end of the element is open and the channels 14, 16 extend from their to the opposite end.

As mentioned above, in the formation of the filter elements shown, an initially flat envelope 6 is first embossed with the relevant set of corrugations 10 ( FIGS. 11 to 14 and 17) or 10 and 12 ( FIGS. 15 and 16), the gaps between them be left smooth and unembossed. When the previously corrugated sheath is placed around the core 24 , the non-embossed parts of the sheath automatically deform so that the circumferential groove 80 into which the channels 16 open out is formed.

As has already been mentioned, the filter elements according to the invention, like the exemplary embodiments illustrated above, will initially be produced as a continuous or endless piece which is cut into pieces with a length corresponding to a straight variety of the final individual elements; these "multiple length sticks" are then further divided into elements of double length and finally separated into the final individual elements during the manufacture of the filter cigarettes. Examples of six-length rods according to the invention, which can be further divided into individual elements according to the invention, are shown schematically in FIGS. 18 to 20. Fig. 18 shows a rod six times the filter length from which individual elements according to Fig. 14 can be made by severing it in the middle of the inner longitudinal corrugated sections, generally first at locations 82 , so that rods double Length and later, during the filter cigarette manufacture described above at locations 84 . A corresponding multi-length rod, but with appropriately different dimensions from the corrugated and circumferentially grooved areas can be cut through the corrugations and grooves to form elements of the type shown in FIG. 17. Fig. 19 shows a six-fold rod, which can be cut first at 82 in the middle of the inner longitudinally corrugated areas and then at 84 in the middle of the circumferentially corrugated areas 12 , and then individual elements are obtained, as shown in Fig. 16 represents are; in the final filter cigarettes, the elements would in this case be arranged in reverse to those in Fig. 15, with the circumferential corrugations 12 at the mouth end; In order to produce the product according to FIG. 15, one can start from a rod according to FIG. 19 which has corrugations 12 at each end. Fig. 20 shows a sextuple rod which can be cut into the corrugated portions 10 and 12 to individual elements, filters and filter cigarettes according to (z. B. Fig. 1) of the invention to produce, which runs in the circumferential direction at one end corrugations have , from which longitudinal corrugations extend to the other end; here the element of the filter cigarette would be oriented in the same way as shown in Fig. 1 with the corrugations 12 in the tobacco rod.

In all of the illustrated exemplary embodiments, the filter core contains a smooth plug casing 4 , but this need not always be present and if it is present, it can be smoke-permeable or smoke-permeable. The individual elements and multi-fold rods, which are shown in FIGS . 14 and 16 to 20, can be provided with a smooth, air-permeable plug casing in the course of filter manufacture. The wrapped elements or filters can then be inserted into a filter cigarette through a ventilation tip wrapper as shown in Figs. 11 and 15, or through a ring tip or ring wrapper.

The present invention thus in particular Smoke filter element with a filter core, a Rauchun permeable cladding that includes the core, at least an inner channel between the impermeable envelope and the core, which is at least at one end of the element is open, and at least one outer channel through the outside of the impermeable envelope is formed and extends to at least one end of the element,  created, also a filter cigarette that such Element and a surrounding the impermeable envelope Contains lace material, which, when smoking on Filter is pulled, a side passage of Outside air in the outer duct or the outer ducts allows. The lace material can be a lace cover sheet or be a tip wrapper through which the filter is inserted into a filter cigarette. The impermeable Envelope can have longitudinal corrugations that the Form channels, which in turn extend the entire length or extend only part of the length of the sheath can. The impermeable covering can be a circumferential groove have that with the outer channel or the outer Channels communicates, with dilution air through the Tip material can enter the groove directly.

Claims (12)

1. cigarette filter with a filter core ( 2 , 4 ) and a smoke-impermeable casing ( 6 ) which bears against and surrounds the core, characterized in that the impermeable casing ( 6 ) has longitudinal corrugations ( 10 ), the inner smoke channels ( 14 ) form between the impermeable casing ( 6 ) and the core ( 2 , 4 ), that the channels are open at at least one end of the filter, and that outer ventilation air channels ( 16 ) between the impermeable casing ( 6 ) and one the impermeable casing ( 6 ) contacting tip wrapping material ( 8 ) are formed which are open at at least one end of the filter; and that the inner channels ( 14 ) are blocked against the passage of smoke through a transverse wall part of the impermeable envelope ( 6 ). 2. Cigarette filter according to claim 1, characterized in that at least the inner channels ( 14 ) extend only over part of the length of the core ( 2 , 4 ). 3. Cigarette filter according to claim 2, characterized in that the inner and outer channels ( 14 , 16 ) are interrupted by a circumferential corrugation ( 12 ) of the impermeable envelope ( 6 ). 4. Cigarette filter according to one of claims 1 to 3, characterized in that the impervious envelope ( 6 ) has a circumferential groove ( 80 ) in which the outer channels ( 16 ) open. 5. Cigarette filter according to claim 1 or 2, characterized characterized in that at least one of the channels at the end or has a constriction in a central region. 6. Cigarette filter according to one of claims 1 to 5, characterized in that the filter core contains at least one filter plug ( 2 ) with a smoke-permeable and / or perforated ( 29 ) plug casing ( 4 ). 7. Cigarette filter according to claim 6, wherein the filter core contains more than one stopper, characterized in that the stopper ( 24 , 26 ; 30 , 32 ) generate different pressure drops. 8. Cigarette filter according to one of claims 1 to 7, characterized in that the smoke-impermeable covering ( 6 ) contains a paper-thermoplastic-paper laminate. 9. Cigarette filter according to one of claims 1 to 8, characterized in that the tip wrapping material is at least partially formed by a tip wrapper ( 8 ) which connects the filter to a wrapped tobacco rod ( 23 ). 10. Filter according to one of claims 1 to 9, characterized in that the tip wrapping material ( 8 ) is a ventilated wrapping which allows the penetration of ambient air through perforation ( 20 ) into the outer channels ( 16 ). 11. Filter element for a cigarette filter according to one of claims 1 to 10, with a filter core ( 2 , 4 ) and a smoke-impermeable casing ( 6 ) which surrounds the core and bears against it, characterized in that the impermeable casing ( 6 ) has longitudinal corrugations ( 10 ) forming inner smoke channels ( 14 ) between the impermeable envelope ( 6 ) and the core ( 2 , 4 ), which are open at at least one end of the filter, that outer ventilation air channels are provided which pass through the outside side of the impermeable casing ( 6 ) are limited and are open at at least one end of the filter; and that the inner channels ( 14 ) are blocked against the flow of smoke through a transverse wall part of the impermeable envelope ( 6 ). 12. A filter element rod having a plurality of filter element units according to claim 11 arranged end-to-end and united by a common impermeable sheath ( 6 ) which extends the full length of the rod, each element unit being mirror-image of the integrally adjacent unit is arranged.